This invention relates to puffer type circuit interrupters, and more specifically relates to a novel puffer interrupter having an increased gas flow pressure during operation, and which permits a dual axial flow of gas through the separating contacts during the interruption operation.
Puffer type interrupters are well known to the art and generally consist of a relatively movable piston and cylinder, one of which is connected to the moving contact of an interrupter device. During interruption, movement of the contact to the open position causes the relative movement of the piston and cylinder to create a high pressure region which forces the flow of gas through the separating contacts, thereby to assist in extinguishing the arc drawn between the contacts. Gas type interrupters are also well known wherein the piston and cylinder are adapted to create a flow of gas in a direction which is along the axis of movement of the movable contacts and which moves axially and along the arc path.
In the prior art puffer type interrupter, one of the limitations on the performance of the device is due to inadequate pressure differential between the high and low pressure regions until relatively late in the opening stroke of the movable contact. Consequently, the necessary contact gap must be larger than optimum for maximum operating performance.
Another limitation on the performance of single pressure buffer type interrupters is that the gas flow is usually only in a single direction along the arc.